Cooling system and laboratory instrument having a cooling system

A laboratory instrument having a cooling system, wherein the cooling system comprises:

• an evaporator;
• a first compressor;
• a second compressor;
• a cooling component;
• an expansion device;
• and
• a line system that connects the evaporator, the first compressor, the second compressor, the cooling component and the expansion device to one another,
• wherein the cooling system comprises a refrigerant, the refrigerant comprising carbon dioxide,
• wherein the first compressor and the second compressor are arranged in series with one another, and
• wherein the cooling system comprises a main circuit, and wherein the main circuit includes:
• the evaporator,
• the first compressor,
• the second compressor,
• the cooling component,
• a high-pressure control apparatus, and
• at least part of the line system,
• and wherein the refrigerant is present in the main circuit;
• wherein the first compressor is designed to compress the refrigerant from a primary pressure range to a secondary pressure range, wherein the secondary pressure range has higher pressures with respect to the primary pressure range;
• wherein the second compressor is designed to compress the refrigerant from the secondary pressure range to a tertiary pressure range, wherein the tertiary pressure range has higher pressures with respect to the secondary pressure range;
• wherein the high-pressure control apparatus is designed to reduce the pressure of the refrigerant from the tertiary pressure range to the secondary pressure range or to reduce the pressure within the tertiary pressure range,
• wherein the high-pressure control apparatus is controlled on the basis of a pressure of the refrigerant downstream of the cooling component and upstream of the high-pressure control apparatus.